Division of Cardiology

A recent study presented by Dr. Luigi Di Biase may very well change the way doctors manage patients with atrial fibrillation who undergo catheter ablation. For years, physicians have used a protocol known as “bridging anticoagulation” (discontinuing warfarin therapy and administering low-molecular-weight heparin during the days surrounding the procedure), with the intention of preventing stroke and hemorrhaging events after catheter ablation. However, performing this procedure without discontinuing a patient’s warfarin and avoiding the heparin "bridge" significantly reduces the occurrence of stroke and bleeding complications, according to Dr. Di Biase’s study.

Luigi Di Biase, MD, PhD, FACC, FHRS

Patients with atrial fibrillation (rapid, uncontrollable heartbeat caused by irregular contraction of the upper two heart chambers) are often prescribed anticoagulants such as warfarin (often known by its brand name Coumadin) due to their high risk of stroke. The radiofrequency catheter ablation procedure, which cauterizes areas of the heart muscle responsible for the arrhythmia, has been highly effective in restoring cardiac sinus rhythm. Conversely, an "iatrogenic" stroke (caused by the procedure itself) can occur, especially in patients with whose atrial fibrillation is persistent.

"Iatrogenic stroke is the worst complication that could happen for an electrophysiologist, so any technique that could reduce this risk is welcome,: said Dr. Di Biase, MD, PhD, FACC, FHRS, Associate Professor of Medicine (Cardiology) at Albert Einstein College of Medicine/Montefiore Medical Center and Senior Researcher at Texas Cardiac Arrhythmia Institute at St. David’s Medical Center, Austin, Texas, USA.

After weighing the risk of bleeding complications vs. the risk of stroke, and questioning whether bridging anticoagulation was actually safer for their patients, Dr. Di Biase and his mentor Andrea Natale, MD, FACC, FHRS, FESC, Executive Medical Director of the Texas Cardiac Arrhythmia Institute, decided to try performing the procedure while maintaining patients’ usual warfarin therapy. The resulting COMPARE trial, the first of its kind, randomly assigned 1,584 patients with non-valvular atrial fibrillation who were at high risk of thromboembolic events with well managed warfarin levels. 790 of the patients discontinued warfarin therapy, and 794 of them continued the therapy, as they underwent the ablation procedure. Thirty-seven of the patients who discontinued warfarin therapy suffered stroke, compared with only two patients in the group that continued therapy. In addition, a significant reduction of minor bleeding was observed in the group of patients that continued warfarin. The study concluded that performing catheter ablation for atrial fibrillation without warfarin discontinuation significantly reduced the occurrence of periprocedural stroke and bleeding complications.

"The possibility we can perform these procedures without Coumadin discontinuation and have a reduced risk of stroke are the important results of our trial," said Dr. Di Biase.

The results of this trial are important so that Dr. Di Biase recommended that the protocol of warfarin discontinuation be replaced entirely. "As new anticoagulants come onto the market, further studies should be conducted to compare the use of these medications during procedures performed without warfarin discontinuation rather than comparing strategies with discontinuation and bridge," he said. "We now know that procedures are less risky if performed without Coumadin discontinuation in high-risk patients, so I believe that studies on the newer anticoagulants should use this strategy rather than the other."